"In 1958, Pope Pius XII approved The Pill for Catholics, so long as its contraceptive effects were “indirect”—that is, so long as it was intended only as a remedy for conditions like painful menses or “a disease of the uterus.” That ruling emboldened Rock still further. Short-term use of The Pill, he knew, could regulate the cycle of women whose periods had previously been unpredictable. Since a regular menstrual cycle was necessary for the successful use of the rhythm method—and since the rhythm method was sanctioned by the Church—shouldn’t it be permissible for women with an irregular menstrual cycle to use the Pill in order to facilitate the use of rhythm? And if that was true why not take the logic one step further? As the federal judge John T. Noonan writes in “Contraception,” his history of the Catholic position on birth control: If it was lawful to suppress ovulation to achieve a regularity necessary for successfully sterile intercourse, why was it not lawful to suppress ovulation without appeal to rhythm? If pregnancy could be prevented by pill plus rhythm, why not by pill alone? In each case suppression of ovulation was used as a means. How was a moral difference made by the addition of rhythm? These arguments, as arcane as they may seem, were central to the development of oral contraception. It was John Rock and Gregory Pincus who decided that the Pill ought to be taken over a four-week cycle—a woman would spend three weeks on the Pill and the fourth week off the drug (or on a placebo), to allow for menstruation. There was and is no medical reason for this."